Method of last protection.



W. A. KRBNTLER.

METHOD OF LAST PROTECTION.

APPLICATION FILED MAR-.31, 191s.

1,092 ,1 1 1. Patented Mar.31, 1914.

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WALTER A. KRENTLEB, OF DETROIT, MICHIGAN, ASSIGNOR TO KRENTLER BROTHERS COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

METHOD 01? LAST PROTECTION.

Specification of Letters Iatent.

Patented Mar. 31, 1914.

Application filed March 31, 1913. Serial No. ?,875.

To all whom it may concern Be it known that I, WALTER A. KRENT- LER, a citizen of the United States, and resident of Detroit, county of Wayne, State of hfichigam'have invented an Improvement in Methods of Last Protection, of which the following description, in connection withthe accompanying drawings, is a specification, like letters on the drawings representlng like parts.

This invention relates to an improved method of protecting wooden lasts.

In the manufacture of shoes, it is necessary to have many different sizes and styles of wooden lasts which are constantly being ut through the machine operations in a shoe factory, such differing styles and sizes being run through in miscellaneous assortments. Such lasts of different sizes and styles are made of different heights, particularly at the heel portion. The distance from the top of the cone to the bottom of the nail clenching plate, usually provided at the heel, is, of course, dependent upon the style and contour, as well as the size of the shoe belng manufactured. In subjecting such shoes to the various machine operations during their manufacture, particularly to the heeling machine operation, it is necessary to ad ust the machine for such different last heights, in order to prevent unnecessary damage to the last. For example, if the heeling machine is set to exert its pressure upon one last of a certain thickness, and a second last of greater thickness is positioned in such machine without the operator noticing the same, or without his changing the heeling machine mechanism to allow for such greater thickness, and the machine is then operated, such second last will be compressed to the thickness of the first last, for which the machine had been set, and, of course, the last will be greatly damaged thereby, the wood being crushed, splintered and distorted in shape. The shoes being subjected to these operations are of constantly varying style, size, and therefore of varying thickness, and machine operators are often careless, since they are usually paid by piece-work they often neglect to stop and change the machines for these different sized lasts. Consequently an undue number of lasts are thus damaged and require repairing at considerable expense.

It is an object of my method to provide a last protecting device which will protect the cone portions of wooden lasts, and which will also enable a large range of varying sizes and styles of last to be made of uniform thickness from the cone to the bottom of the clenching plate, so that heeling machines and the like need not be re-set for each style and size of last being operated thereon.

My method also contemplates the provision of a protecting plate which will serve as a. substantial thickness of wood at the heel portion of lasts, while permitting the shoe upper to follow the designed curve or contour of any particular style at the heel.

Preferably my novel method consists in applying to the cone portions of lasts a metallic protecting device of varying thickness for each style or size of last having a different thickness in the heel portion so that all such varying lasts provided with my device are of uniform thickness at the heel. Preferably also, I provide a protecting device which may be secured to a wooden last in substantially the same manner irrespective of the thickness of the protector to be added thereto, so that the same securing means may be employed to unite to the last protectors of different thickness, rendering the same interchangeable. This interchangeability is furthermore important because should one style last, provided with my protector at the cone have the cone portion of the wood damaged and cut away, a protector of greater thickness could be applied to the last to build it up to its normal desired thiclkness from the top to the bottom of the hee It will be understood that my method is not limited to any particular form of protector or securing means therefor, although a suitable protector and one which I prefer to employ, is herein illustrated, but is not herein specifically claimed, being the subject matter of a copending application thereon.

My novel method of heel protection resides ehiefly in so protecting lasts of variable thickness at the heel so that they may be made all of one standard or uniform thickness, and I believe that this method is a distinct novelty in the art of last protection, and therefore wish to claim the same broadly.

My novel method will be more clearly understood n reference to the attached drawings, showing a convenientform of protector, suitable to carry out my method.

Referring to the drawings, wherein a preferred embodiment of the invention is illustrated, Figure 1 is a side view of a last with a portion of the cone shown in section; and

Fig. 2'is a top plan view of the last and pro-- tecting plate.

My invention may be applied to any type of last, being herein illustrated in connection with a well known hinged'last, the last comprising a heel part 1 and a forepart 2. The heel part 1 has the top of the cone portion 3 substantially level, and has a central socket 4 bored therein, which socket may be of suitable diameter to fit the standard size spindle of the shoe machines, and therefore is of less diameter than that ordinarily required, the entire thickness of the ordinary thimble being left in the wood of the heel, and this much added strength thereby secured, Additional sockets 5 and 6 are also formed in the heel parallel with the socket 4, and at the rear and front thereof, respectively. These sockets are of different depths, both as to each other, and difierent from that of the spindle socket 4, thus'securing the advantages of staggering the depth of the sockets which will obviate largely the tendency of the wood to split.

Preferably the forward socket 6 is of less depth than the rear socket 5, the latter being in the line of greater pressure during the heeling machine operations, and it being therefore desirable to have the same more firmly seated in the heavier part of the wood constituting the heel portion of the last. To the last so prepared I apply a protector, preferably of metal, and comprising a plate 7, having therein a central aperture 8 to register with the spindle socket 4, and having formed integrally therewith or welded securely thereto, downwardly projecting studs 9 and 10 in a position and of a diameter and length to firmly fit in the sockets 5 and 6 respectively. Such fit is preferably a driving fit, and preferably also the length of these studs 9 and 10 is slightly greater than the depth of the sockets 5 and 6, so that in driving the plate 7 home until it is firmly seated on the top 3 of the cone, the lower ends of the members 9 and 10 will act to compress the wood of the last slightly at the points 11 and 12 respectively, so that at these points a very substantial amount of pressure will be supported by the wood of the last, thus relieving the cone surface 3 very substantially from the pressures to which the last may be subjected.

lBy having the plate 7 of a substantial depth approximately as shown in Fig. 2, a construction is provided which enables the ordinary last thimble to be eliminated, the member 7 protecting the opening of the socket at, and the entire plate 7, by means of its damage it.

In order to hold the plate 7 securely to the wood of the heel part 1, as well as to strengthen the narrow cone portion and counteract the tendency to split the same, I

provide the edge portions of the studs 9 and 10 with notches 13 and i l and two bolts 15 .7

and 16, arearra-nged transversely through the cone portion 1, lntersectlng the sockets 5 and 6, ina position to cooperate with the notches 13 and 14 to hold the'studs 9 and 10 firmly seated. Preferably these bolts 15 and 16 are of the well known type, provided with enlarged heads bearing on the outer surfaces of the last at either end as indicated at 17 and 18 in Fig. 1. These bolts are also preferably staggered as indicated in Fig. 2, and'are arranged to pass through the last on the inner edges of the studs 9 and 10 between the same and the spindle socket 4, so that any strain exerted thereon will be toward said socket, and it will also tend to counteract the torsional strains exerted on the walls of said socket by a machine spindle. The plate 7 is preferablyv of slightly less area than the top surface 3 of the cone of the last 011 which it is applied, particularly at the extreme rear portion, in order not to interfere with the shoe upper and also to permit the variation in styles of heel contours without a corresponding variation in the form of the plate 7.

I provide the notches 13 and It in the studs 9 and 10 with the upper walls thereof inclined for a short distance, and with the lower walls substantially in contact with the bolts 15 and 16, as clearly shown in Fig. 2. This feature is of importance, because during the applications of pressure on the plate 7, the entire plate and the studs 9 and 10 may be forcedslightly downward relatively with the wooden upper inclined walls of said notches permit this yield without affecting the bolts 15 and 16. The withdrawal, however, of the plate 7 is prevented by said bolts, and therefore the entire plate will be firmly held in proper position on the heel part 1 of the last. A heel'plate 19 isalso illustrated andthe entire thickness of the heel of a last is con.- sidered as from the bottom of the 19 to the top surface 20 of the plate 7. I

It is customary to refer to the heel height heel plate of a last as varying in irons, and accordingly I preferably arrange the thickness of the plate 7 as correspondingly varying in a specified number of irons but any other degree of thickness may be made as desired. The top surface 20 of the plate 7 is also preferably rounded somewhat, which will prevent swaging and marring the plate, and will allow the entire last to rock upon a machine spindle block. To illustrate the varyin thickness of the plate 7 the thickness of the smaller sized irons are indicated in dotted lines at 21, 22, and 23, in Fig. 2, the different heights of lasts being correspondingly indicated, it being understood that such thinner plates are of the same length, breadth and form, but simply of less thickness than the plate 7 and to each of these thinner plates 21, 22, and 23, are secured studs identical with those indicated at 9 and 10. Thus when my method is utilized in connection with any sized last, the same spindle sockets and other borings are made and to the same depth, irrespective of the thickness of the last, a suitable iron being then applied which will bring the combined iron and wood of the heel portion up to the standard height or thickness. I

The importance of my novel method of last rotection will be readily appreciated by those skilled in the art, the problem of protecting lasts being one which inventors have been constantly striving to solve successfully, particularly in connection with the modern high speed and powerful machines now used almost exclusively in shoe manufacture. The variations in height of the of course, necessary, owing variation in styles of shoes, different sizes made for heel portion are, to the continual as well as to the each style.

The heeling machine operation is the severest to which a wooden last is subjected during the manufacture of a shoethereon, and almost any wooden last can be broken at a single operation by the heeling machine operator, if he fails to adjust properly his machine for the particular height of last to be operated upon. method of lasting, however, all danger of breaking wooden lasts from this cause is eliminated, and furthermore a specially advantageous form and functions may be utilized.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

That improvement in the art of protecting wooden lasts during the heeling machine operation, which consists in building up the heel portions of the wooden lasts of variable thicknesses by the addition of plates of in versely corresponding variable thicknesses, whereby the height at the heel of all lasts will be substantially uniform and will permit the heeling operation thereon under substantially the same compression.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

WALTER A. KRENTLER.

Witnesses:

W. Gr. GILMORE, N. E. CHAVENELLE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0.

By means of my 

